If the amount of energy given off when drawing energy from a given compound is more negative than -7.3 (e.g. -7.9 kcal) it is a high energy compound. If more positive, the compound is called a low energy compound.

How do we make ATP

Two ways: substrate level phosphorylation, oxidative phosphorylation.

Comparison of the two methods

~6 ATP are made via substrate level phosphorylation in the round of glycolysis and Krebs cycle.

Anaerobic organisms have only substrate level phosphorylation

This type occurs twice in gylcolysis and once in the Krebs cycle.

34 ATP per glucose molecule are made via oxidative phosphorylation.

This occurs in the Krebs cycle.

Substrate Level Phosphorylation

There are three of these types of these reactions: one in glycolysis, two in Krebs cycle.

We have substrates that have more than -7.3 kcal potential energy in them so we break them down to release that energy and put it into making an ATP.